handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt, empty, writeFile)
+import Prelude hiding (lookup, concat, replicate, splitAt, take)
import System.IO (Handle, BufferMode(..), hSetBuffering)
-import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, writeFile)
-import Data.ByteString.Lazy (fromStrict, fromChunks)
-import qualified Data.ByteString.Char8 as BC (replicate, pack, length)
+import Data.ByteString (ByteString, unpack, concat, hGet, hPut, take, empty)
+import qualified Data.ByteString.Char8 as BC (length)
import Network (connectTo, PortID(..))
-import Data.Binary (Binary(..), decode)
-import Data.Binary.Put (putWord32be, putWord16be, putWord8)
-import Data.Binary.Get (getWord32be, getWord16be, getWord8, runGet)
-import Control.Monad (replicateM, liftM, forever)
-import Control.Applicative ((<$>), liftA3)
+import Control.Monad.State
import Data.Bits
import Data.Word (Word8)
-import Data.Map (Map(..), fromList)
+import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust)
+import qualified Crypto.Hash.SHA1 as SHA1 (hash)
import FuncTorrent.Metainfo (Info(..), Metainfo(..))
-import FuncTorrent.Utils (splitN)
+import FuncTorrent.Utils (splitN, splitNum)
+import FuncTorrent.Fileops (createDummyFile, writeFileAtOffset)
+import FuncTorrent.PeerMsgs (Peer(..), PeerMsg(..), sendMsg, getMsg, genHandshakeMsg)
-type ID = String
-type IP = String
-type Port = Integer
+data PState = PState { handle :: Handle
+ , peer :: Peer
+ , meChoking :: Bool
+ , meInterested :: Bool
+ , heChoking :: Bool
+ , heInterested :: Bool}
-data PeerState = PeerState { handle :: Handle
- , am_choking :: Bool
- , am_interested :: Bool
- , peer_choking :: Bool
- , peer_interested :: Bool}
-
--- Maintain info on every piece and the current state of it.
--- should probably be a TVar.
-type Pieces = [PieceData]
+type PeerState = State PState
data PieceDlState = Pending
| InProgress
| Have
- deriving (Show)
+ deriving (Show, Eq)
-- todo - map with index to a new data structure (peers who have that piece amd state)
data PieceData = PieceData { peers :: [Peer] -- ^ list of peers who have this piece
- , state :: PieceDlState -- ^ state of the piece from download perspective.
- , hash :: ByteString } -- ^ piece hash
+ , dlstate :: PieceDlState -- ^ state of the piece from download perspective.
+ , hash :: ByteString -- ^ piece hash
+ , len :: Integer } -- ^ piece length
-- which piece is with which peers
type PieceMap = Map Integer PieceData
--- | Peer is a PeerID, IP address, port tuple
-data Peer = Peer ID IP Port
- deriving (Show, Eq)
-
-data PeerMsg = KeepAliveMsg
- | ChokeMsg
- | UnChokeMsg
- | InterestedMsg
- | NotInterestedMsg
- | HaveMsg Integer
- | BitFieldMsg ByteString
- | RequestMsg Integer Integer Integer
- | PieceMsg Integer Integer ByteString
- | CancelMsg Integer Integer Integer
- | PortMsg Port
- deriving (Show)
-- Make the initial Piece map, with the assumption that no peer has the
-- piece and that every piece is pending download.
-mkPieceMap :: Integer -> ByteString -> Map Integer PieceData
-mkPieceMap numPieces pieceHash = fromList kvs
+mkPieceMap :: Integer -> ByteString -> [Integer] -> PieceMap
+mkPieceMap numPieces pieceHash pLengths = fromList kvs
where kvs = [(i, PieceData { peers = []
- , state = Pending
- , hash = h }) | (i, h) <- zip [0..numPieces] hashes]
- hashes = splitN (fromIntegral numPieces) pieceHash
-
-genHandShakeMsg :: ByteString -> String -> ByteString
-genHandShakeMsg infoHash peer_id = concat [pstrlen, pstr, reserved, infoHash, peerID]
- where pstrlen = singleton 19
- pstr = BC.pack "BitTorrent protocol"
- reserved = BC.replicate 8 '\0'
- peerID = BC.pack peer_id
-
-handShake :: Peer -> ByteString -> String -> IO Handle
-handShake (Peer _ ip port) infoHash peerid = do
- let hs = genHandShakeMsg infoHash peerid
+ , dlstate = Pending
+ , hash = h
+ , len = pLen })
+ | (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
+ hashes = splitN 20 pieceHash
+
+havePiece :: PieceMap -> Integer -> Bool
+havePiece pm index =
+ dlstate (pm ! index) == Have
+
+connectToPeer :: Peer -> IO Handle
+connectToPeer (Peer _ ip port) = do
h <- connectTo ip (PortNumber (fromIntegral port))
hSetBuffering h LineBuffering
- hPut h hs
- rlenBS <- hGet h (length (unpack hs))
- putStrLn $ "got handshake from peer: " ++ show rlenBS
return h
-instance Binary PeerMsg where
- put msg = case msg of
- KeepAliveMsg -> putWord32be 0
- ChokeMsg -> do putWord32be 1
- putWord8 0
- UnChokeMsg -> do putWord32be 1
- putWord8 1
- InterestedMsg -> do putWord32be 1
- putWord8 2
- NotInterestedMsg -> do putWord32be 1
- putWord8 3
- HaveMsg i -> do putWord32be 5
- putWord8 4
- putWord32be (fromIntegral i)
- BitFieldMsg bf -> do putWord32be $ fromIntegral (1 + bfListLen)
- putWord8 5
- mapM_ putWord8 bfList
- where bfList = unpack bf
- bfListLen = length bfList
- RequestMsg i o l -> do putWord32be 13
- putWord8 6
- putWord32be (fromIntegral i)
- putWord32be (fromIntegral o)
- putWord32be (fromIntegral l)
- PieceMsg i o b -> do putWord32be $ fromIntegral (9 + blocklen)
- putWord8 7
- putWord32be (fromIntegral i)
- putWord32be (fromIntegral o)
- mapM_ putWord8 blockList
- where blockList = unpack b
- blocklen = length blockList
- CancelMsg i o l -> do putWord32be 13
- putWord8 8
- putWord32be (fromIntegral i)
- putWord32be (fromIntegral o)
- putWord32be (fromIntegral l)
- PortMsg p -> do putWord32be 3
- putWord8 9
- putWord16be (fromIntegral p)
- get = do
- l <- getWord32be
- msgid <- getWord8
- case msgid of
- 0 -> return ChokeMsg
- 1 -> return UnChokeMsg
- 2 -> return InterestedMsg
- 3 -> return NotInterestedMsg
- 4 -> liftM (HaveMsg . fromIntegral) getWord32be
- 5 -> liftM (BitFieldMsg . pack) (replicateM (fromIntegral l - 1) getWord8)
- 6 -> liftA3 RequestMsg getInteger getInteger getInteger
- where getInteger = fromIntegral <$> getWord32be
- 7 -> liftA3 PieceMsg getInteger getInteger (pack <$> replicateM (fromIntegral l - 9) getWord8)
- where getInteger = fromIntegral <$> getWord32be
- 8 -> liftA3 CancelMsg getInteger getInteger getInteger
- where getInteger = fromIntegral <$> getWord32be
- 9 -> liftM (PortMsg . fromIntegral) getWord16be
- _ -> error ("unknown message ID: " ++ show msgid)
-
-getMsg :: Handle -> IO PeerMsg
-getMsg h = do
- lBS <- hGet h 4
- let l = bsToInt lBS
- if l == 0
- then return KeepAliveMsg
- else do
- msg <- hGet h l
- return $ decode $ fromStrict $ concat [lBS, msg]
-
-
-bsToInt :: ByteString -> Int
-bsToInt x = fromIntegral (runGet getWord32be (fromChunks (return x)))
+doHandshake :: Handle -> Peer -> ByteString -> String -> IO ()
+doHandshake h peer infoHash peerid = do
+ let hs = genHandshakeMsg infoHash peerid
+ hPut h hs
+ putStrLn $ "--> handhake to peer: " ++ show peer
+ _ <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show peer
+ return ()
bitfieldToList :: [Word8] -> [Integer]
bitfieldToList bs = go bs 0
where go [] _ = []
go (b:bs') pos =
- let setBits = [pos*8 + (toInteger i) | i <- [0..8], testBit b i]
+ let setBits = [pos*8 + toInteger i | i <- [0..8], testBit b i]
in
- setBits ++ (go bs' (pos + 1))
-
--- downloadPiece :: Integer -> Handle -> IO ()
-
-createDummyFile :: FilePath -> Int -> IO ()
-createDummyFile path size = do
- writeFile path (BC.replicate size '\0')
-
--- loop1 :: shake hands with all peers, find out the pieces they have, form PieceData.
--- recvMsg :: Peer -> Handle -> Msg
-msgLoop :: Handle -> ByteString -> IO ()
-msgLoop h pieceHash =
- let numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
- pieceStatus = mkPieceMap numPieces pieceHash
+ setBits ++ go bs' (pos + 1)
+
+-- helper functions to manipulate PeerState
+toPeerState :: Handle -> Peer -> Bool -> Bool -> Bool -> Bool -> PState
+toPeerState h p meCh meIn heCh heIn =
+ PState { handle = h
+ , peer = p
+ , heChoking = heCh
+ , heInterested = heIn
+ , meChoking = meCh
+ , meInterested = meIn }
+
+-- -- recvMsg :: Peer -> Handle -> Msg
+-- msgLoop :: PeerState -> PieceMap -> FilePath -> IO ()
+-- msgLoop pState@(PeerState { meInterested = False, heChoking = True }) pieceStatus file = do
+-- -- if me NOT Interested and she is Choking, tell her that
+-- -- I am interested.
+-- let h = handle pState
+-- sendMsg h InterestedMsg
+-- putStrLn $ "--> InterestedMsg to peer: " ++ show (peer pState)
+-- msgLoop (pState { meInterested = True }) pieceStatus file
+-- msgLoop pState@(PeerState { meInterested = True, heChoking = False }) pieceStatus file =
+-- -- if me Interested and she not Choking, send her a request
+-- -- for a piece.
+-- case pickPiece pieceStatus of
+-- Nothing -> putStrLn "Nothing to download"
+-- Just workPiece -> do
+-- let pLen = len (pieceStatus ! workPiece)
+-- putStrLn $ "piece length = " ++ show pLen
+-- pBS <- downloadPiece (handle pState) workPiece pLen
+-- if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
+-- then
+-- putStrLn $ "Hash mismatch: " ++ show (hash (pieceStatus ! workPiece)) ++ " vs " ++ show (take 20 (SHA1.hash pBS))
+-- else do
+-- let fileOffset = if workPiece == 0 then 0 else workPiece * len (pieceStatus ! (workPiece - 1))
+-- putStrLn $ "Write into file at offset: " ++ show fileOffset
+-- writeFileAtOffset file fileOffset pBS
+-- msgLoop pState (adjust (\pieceData -> pieceData { state = Have }) workPiece pieceStatus) file
+-- msgLoop pState pieceStatus file = do
+-- msg <- getMsg (handle pState)
+-- putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
+-- case msg of
+-- KeepAliveMsg -> do
+-- sendMsg (handle pState) KeepAliveMsg
+-- putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
+-- msgLoop pState pieceStatus file
+-- BitFieldMsg bss -> do
+-- let pieceList = bitfieldToList (unpack bss)
+-- pieceStatus' = updatePieceAvailability pieceStatus (peer pState) pieceList
+-- putStrLn $ show (length pieceList) ++ " Pieces"
+-- -- for each pieceIndex in pieceList, make an entry in the pieceStatus
+-- -- map with pieceIndex as the key and modify the value to add the peer.
+-- -- download each of the piece in order
+-- msgLoop pState pieceStatus' file
+-- UnChokeMsg ->
+-- msgLoop (pState { heChoking = False }) pieceStatus file
+-- _ ->
+-- msgLoop pState pieceStatus file
+
+-- simple algorithm to pick piece.
+-- pick the first piece from 0 that is not downloaded yet.
+pickPiece :: PieceMap -> Maybe Integer
+pickPiece m =
+ let pieceList = toList m
+ allPending = filter (\(_, v) -> dlstate v == Pending) pieceList
in
- forever $ do
- msg <- getMsg h
- putStrLn $ "got a " ++ show msg
- case msg of
- BitFieldMsg bss -> do
- let pieceList = bitfieldToList (unpack bss)
- putStrLn (show pieceList)
- -- download each of the piece in order
- _ -> putStrLn (show msg)
-
-handlePeerMsgs :: Peer -> Metainfo -> String -> (String -> IO ()) -> IO ()
-handlePeerMsgs p m peerId logFn = do
- h <- handShake p (infoHash m) peerId
- logFn $ "handShake"
- msgLoop h (pieces (info m))
-
+ case allPending of
+ [] -> Nothing
+ ((i, _):_) -> Just i
+
+updatePieceAvailability :: PieceMap -> Peer -> [Integer] -> PieceMap
+updatePieceAvailability pieceStatus p pieceList =
+ mapWithKey (\k pd -> if k `elem` pieceList
+ then (pd { peers = p : peers pd })
+ else pd) pieceStatus
+
+handlePeerMsgs :: Peer -> Metainfo -> String -> IO ()
+handlePeerMsgs p m peerId = do
+ h <- connectToPeer p
+ doHandshake h p (infoHash m) peerId
+ let pstate = toPeerState h p False True False True
+ pieceHash = pieces (info m)
+ numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+ pLen = pieceLength (info m)
+ fileLen = lengthInBytes (info m)
+ fileName = name (info m)
+ pieceStatus = mkPieceMap numPieces pieceHash (splitNum fileLen pLen)
+ createDummyFile fileName (fromIntegral fileLen)
+ (r, _) <- runStateT (msgLoop pieceStatus fileName) pstate
+ return ()
+
+msgLoop :: PieceMap -> FilePath -> StateT PState IO ()
+msgLoop pieceStatus file =
+ StateT(\pState -> do
+ let h = handle pState
+ msg <- getMsg h
+ liftIO $ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
+ case msg of
+ KeepAliveMsg -> do
+ sendMsg h KeepAliveMsg
+ liftIO $ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
+ runStateT (msgLoop pieceStatus file) pState)
+
+downloadPiece :: Handle -> Integer -> Integer -> IO ByteString
+downloadPiece h index pieceLength = do
+ let chunks = splitNum pieceLength 16384
+ liftM concat $ forM (zip [0..] chunks) (\(i, pLen) -> do
+ sendMsg h (RequestMsg index (i*pLen) pLen)
+ putStrLn $ "--> " ++ "RequestMsg for Piece "
+ ++ show index ++ ", part: " ++ show i ++ " of length: "
+ ++ show pLen
+ msg <- getMsg h
+ case msg of
+ PieceMsg index begin block -> do
+ putStrLn $ " <-- PieceMsg for Piece: "
+ ++ show index
+ ++ ", offset: "
+ ++ show begin
+ return block
+ _ -> do
+ putStrLn "ignoring irrelevant msg"
+ return empty)
+
+verifyHash :: ByteString -> ByteString -> Bool
+verifyHash bs pieceHash =
+ take 20 (SHA1.hash bs) == pieceHash
projects / functorrent.git / blobdiff